TB 1-1520-238-20-89
(2) Ferry Status. Same as paragraph la. Those aircraft that have a DD 250 and are at Boeing, Mesa, will be
inspected prior to ferry to final destination.
e. Maintenance Trainers (Category A and B). Same as paragraph la.
f. Components/Parts in Stock at All Levels (Depot and Others) including War Reserves.
For assets in wholesale stock the inspection in paragraph 8 is not required until receipt by a retail activity.
For stock at retail activities: Zero Time Strap Packs do not require inspection until the next 125 hour inspection. This
Technical Bulletin (TB) will be complied with on all Strap Packs prior to installation.
g. Components/Parts in Work (Depot Level and Others). Items listed in paragraphs 6 and 7 in work will not be
issued until compliance with this TB is completed.
2.
Task/lnspection Suspense Date. Within next 50 flight hours.
3.
4.
Summary of Problem.
NOTE
This message contains two separate inspections.
a. History.
(1) Main Rotor Strap Pack. Cracks may develop around the inner diameter of the outboard main rotor strap
pack bolt. Task entails a Fluorescent Dye Penetrate Inspection of all Outboard Main Rotor Strap Pack Bolts.
NOTE
Lead Lag Links -11 configuration must be removed for the Bearing Inspection in
the following task.
(2) Lead Lag Link Assembly. Several maintenance activities have recently found Teflon Liners in Sleeve
Bearings (P/N 7-311411154-1) of the Lead Lag Link (P/N 7-311411155-11) debonding/deteriorating. This deterioration is
occurring after a very short period of use. All premature Sleeve Bearing failures have been traced to a single vendor,
Southwest Products (SWPCO, Cage 81376). Task entails the removal of the -11 configuration Lead Lag Links and visual
inspection of Sleeve Bearings for serviceability.
c. The purpose of this message.
(1) Direct a one time and recurring inspection of all Strap Pack Outboard Bolts for cracks. All strap packs with
flight hours will be inspected within the next 50 flight hours and each 125 flight hours thereafter.
(2) Direct a one-time inspection of all AH-64 Aircraft to determine if any 7-311411155-11 (dash 11) Lead Lag
Links are installed. If so, disassemble and inspect for Sleeve Bearings manufactured by Southwest Products in the link as
well as the condition of the Teflon. A 50 flight hour recurring inspection of all aircraft with sleeve bearings manufactured
by Southwest Products are required.
(3) The 50-hour and 125 hour inspection intervals were chosen to allow aligning the inspections with scheduled
Phase Maintenance Inspections. Every effort should be made to coordinate inspections so that all Strap Packs on each
Main Rotor Hub Assembly are inspected at the same time.
5. End items to be inspected. All AH-64 Aircraft.
6. Assembly components to be inspected.
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